Honestly I think it depends on the size you're looking at and the tasks you have for it. If all you ever plan on doing is pulling a 6' bush hog, most any brand in the 28-30 HP range will do so, depending on terrain. Lots of hills? You may want more power. Main thing is it feels comfortable under your backside for your given task. I'd advise some "test drives" at the dealers.
If you have specific tasks that require certain abilities, study the numbers of the spec sheets. If you need to be able to lift X amount of weight, you want to be sure you're choice will do it.
When I was making my choice, my primary task for my machine was to fit into certain areas, and move earth. I couldn't go much larger than the average sized 40HP unit, but needed the weight for stability on my hills, as well as to provide the digging forces needed to move earth easily. What it boiled down to for me, which was hands down the best choice, was my 4035.
I do agree with him that I'd never own a new Deere.